Joshua C Koch, Ph.D.
Surface water / groundwater interactions; hyporheic zone hydrology and biogeochemistry; carbon, nitrogen, and phosphorus cycling; flow above / through frozen ground; preferential flow and soil pipe formation and transport.
Professional Experience
2011 - Present Research Hydrologist, U.S. Geological Survey (USGS), Anchorage, AK
2006 - 2011 Student Hydrologist, Branch of Regional Research, USGS, Boulder, CO
2005 - 2006 Research Assistant, Institute of Alpine and Arctic Research, University of Colorado, Boulder
2003 - 2005 Research Assistant, Semi-Arid Hydrology and Riparian Areas, University of Arizona, Tucson, AZ
2002 - 2003 Hydrologist Intern, Branch of Regional Research, USGS, Lakewood, CO
2001 - 2002 Hydrologist Intern, MA-RI Water District, USGS, Northborough, MA
Education and Certifications
PhD 2010 University of Colorado, Boulder, CO Civil, Environmental, and Architectural Engineering
MS 2005 University of Arizona, Tucson, AZ Department of Hydrology
BA 2001 Wesleyan University, Middletown, CT Earth and Environmental Sciences
Affiliations and Memberships*
American Geophysical Union, Hydrology and Cryosphere Sections
American Water Resources Association - Alaska Chapter
Association of Polar Early Career Scientists
Science and Products
Filter Total Items: 17
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Dissolved organic carbon and nitrogen release from boreal Holocene permafrost and seasonally frozen soils of Alaska Dissolved organic carbon and nitrogen release from boreal Holocene permafrost and seasonally frozen soils of Alaska
Permafrost (perennially frozen) and active-layer (seasonally thawed) soils varying in soil carbon (C) and nitrogen (N) content and radiocarbon age were collected from three sites in interior Alaska to determine potential release of dissolved organic carbon (DOC), total dissolved N (TDN), dissolved organic nitrogen (DON), and dissolved inorganic nitrogen (DIN) upon thaw. Soil cores were...
Filter Total Items: 65
No results found.
Filter Total Items: 59
Permafrost hydrology drives the assimilation of old carbon by stream food webs in the Arctic Permafrost hydrology drives the assimilation of old carbon by stream food webs in the Arctic
Permafrost thaw in the Arctic is mobilizing old carbon (C) from soils to aquatic ecosystems and the atmosphere. Little is known, however, about the assimilation of old C by aquatic food webs in Arctic watersheds. Here, we used C isotopes (δ13C, Δ14C) to quantify C assimilation by biota across 12 streams in arctic Alaska. Streams spanned watersheds with varying permafrost hydrology, from...
Authors
Jonathon A O'Donnell, Michael P. Carey, Joshua C. Koch, Xiaomei Xu, Brett Poulin, Jennifer Walker, Christian E. Zimmerman
Soil physical, hydraulic, and thermal properties in interior Alaska, USA: Implications for hydrologic response to thawing permafrost conditions Soil physical, hydraulic, and thermal properties in interior Alaska, USA: Implications for hydrologic response to thawing permafrost conditions
Boreal forest regions are a focal point for investigations of coupled water and biogeochemical fluxes in response to wildfire disturbances, climate warming, and permafrost thaw. Soil hydraulic, physical, and thermal property measurements for mineral soils in permafrost regions are limited, despite substantial influences on cryohydrogeologic model results. This work expands mineral soil...
Authors
Brian A. Ebel, Joshua C. Koch, Michelle A. Walvoord
Ice wedge degradation and stabilization impacts water budgets and nutrient cycling in Arctic trough ponds Ice wedge degradation and stabilization impacts water budgets and nutrient cycling in Arctic trough ponds
Trough ponds are ubiquitous features of Arctic landscapes and an important component of freshwater aquatic ecosystems. Permafrost thaw causes ground subsidence, creating depressions that gather water, creating ponds. Permafrost thaw also releases solutes and nutrients, which may fertilize these newly formed ponds. We measured water budget elements and chloride, ammonium, and dissolved...
Authors
Joshua C. Koch, M. Torre Jorgenson, Kimberly P. Wickland, Mikhail Z. Kanevskiy, Robert G. Striegl
Comparative nest survival of three sympatric loon species breeding in the Arctic Comparative nest survival of three sympatric loon species breeding in the Arctic
Identifying factors influencing nest survival among sympatric species is important for understanding and managing sources of variation in population dynamics of individual species. Three species of loons nest sympatrically in northern Alaska and differ in body size, life history characteristics, and population trends. We tested the effects of competition, nest site selection, and water...
Authors
Brian D. Uher-Koch, Joshua C. Koch, Kenneth G. Wright, Joel A. Schmutz
Dissolved organic carbon and nitrogen release from boreal Holocene permafrost and seasonally frozen soils of Alaska Dissolved organic carbon and nitrogen release from boreal Holocene permafrost and seasonally frozen soils of Alaska
Permafrost (perennially frozen) soils store vast amounts of organic carbon (C) and nitrogen (N) that are vulnerable to mobilization as dissolved organic carbon (DOC) and dissolved organic and inorganic nitrogen (DON, DIN) upon thaw. Such releases will affect the biogeochemistry of permafrost regions, yet little is known about the chemical composition and source variability of active...
Authors
Kimberly P. Wickland, Mark P. Waldrop, George R. Aiken, Joshua C. Koch, M. Torre Jorgenson, Robert G. Striegl
Nutrient dynamics in partially drained arctic thaw lakes Nutrient dynamics in partially drained arctic thaw lakes
Thaw lakes are ubiquitous on arctic coastal plains (ACPs). While many thaw lakes have steep banks, stable water levels, and static surface areas, others only partially fill their basins and vary in area over the summer. These partially drained lakes (PDLs) are hydrologically connected to the wetlands immediately surrounding them. Heat and nutrient availability limit aquatic productivity...
Authors
Joshua C. Koch, Tom F. Fondell, Joel A. Schmutz, Sarah M. Laske
Science and Products
Filter Total Items: 17
Filter Total Items: 31
Dissolved organic carbon and nitrogen release from boreal Holocene permafrost and seasonally frozen soils of Alaska Dissolved organic carbon and nitrogen release from boreal Holocene permafrost and seasonally frozen soils of Alaska
Permafrost (perennially frozen) and active-layer (seasonally thawed) soils varying in soil carbon (C) and nitrogen (N) content and radiocarbon age were collected from three sites in interior Alaska to determine potential release of dissolved organic carbon (DOC), total dissolved N (TDN), dissolved organic nitrogen (DON), and dissolved inorganic nitrogen (DIN) upon thaw. Soil cores were...
Filter Total Items: 65
No results found.
Filter Total Items: 59
Permafrost hydrology drives the assimilation of old carbon by stream food webs in the Arctic Permafrost hydrology drives the assimilation of old carbon by stream food webs in the Arctic
Permafrost thaw in the Arctic is mobilizing old carbon (C) from soils to aquatic ecosystems and the atmosphere. Little is known, however, about the assimilation of old C by aquatic food webs in Arctic watersheds. Here, we used C isotopes (δ13C, Δ14C) to quantify C assimilation by biota across 12 streams in arctic Alaska. Streams spanned watersheds with varying permafrost hydrology, from...
Authors
Jonathon A O'Donnell, Michael P. Carey, Joshua C. Koch, Xiaomei Xu, Brett Poulin, Jennifer Walker, Christian E. Zimmerman
Soil physical, hydraulic, and thermal properties in interior Alaska, USA: Implications for hydrologic response to thawing permafrost conditions Soil physical, hydraulic, and thermal properties in interior Alaska, USA: Implications for hydrologic response to thawing permafrost conditions
Boreal forest regions are a focal point for investigations of coupled water and biogeochemical fluxes in response to wildfire disturbances, climate warming, and permafrost thaw. Soil hydraulic, physical, and thermal property measurements for mineral soils in permafrost regions are limited, despite substantial influences on cryohydrogeologic model results. This work expands mineral soil...
Authors
Brian A. Ebel, Joshua C. Koch, Michelle A. Walvoord
Ice wedge degradation and stabilization impacts water budgets and nutrient cycling in Arctic trough ponds Ice wedge degradation and stabilization impacts water budgets and nutrient cycling in Arctic trough ponds
Trough ponds are ubiquitous features of Arctic landscapes and an important component of freshwater aquatic ecosystems. Permafrost thaw causes ground subsidence, creating depressions that gather water, creating ponds. Permafrost thaw also releases solutes and nutrients, which may fertilize these newly formed ponds. We measured water budget elements and chloride, ammonium, and dissolved...
Authors
Joshua C. Koch, M. Torre Jorgenson, Kimberly P. Wickland, Mikhail Z. Kanevskiy, Robert G. Striegl
Comparative nest survival of three sympatric loon species breeding in the Arctic Comparative nest survival of three sympatric loon species breeding in the Arctic
Identifying factors influencing nest survival among sympatric species is important for understanding and managing sources of variation in population dynamics of individual species. Three species of loons nest sympatrically in northern Alaska and differ in body size, life history characteristics, and population trends. We tested the effects of competition, nest site selection, and water...
Authors
Brian D. Uher-Koch, Joshua C. Koch, Kenneth G. Wright, Joel A. Schmutz
Dissolved organic carbon and nitrogen release from boreal Holocene permafrost and seasonally frozen soils of Alaska Dissolved organic carbon and nitrogen release from boreal Holocene permafrost and seasonally frozen soils of Alaska
Permafrost (perennially frozen) soils store vast amounts of organic carbon (C) and nitrogen (N) that are vulnerable to mobilization as dissolved organic carbon (DOC) and dissolved organic and inorganic nitrogen (DON, DIN) upon thaw. Such releases will affect the biogeochemistry of permafrost regions, yet little is known about the chemical composition and source variability of active...
Authors
Kimberly P. Wickland, Mark P. Waldrop, George R. Aiken, Joshua C. Koch, M. Torre Jorgenson, Robert G. Striegl
Nutrient dynamics in partially drained arctic thaw lakes Nutrient dynamics in partially drained arctic thaw lakes
Thaw lakes are ubiquitous on arctic coastal plains (ACPs). While many thaw lakes have steep banks, stable water levels, and static surface areas, others only partially fill their basins and vary in area over the summer. These partially drained lakes (PDLs) are hydrologically connected to the wetlands immediately surrounding them. Heat and nutrient availability limit aquatic productivity...
Authors
Joshua C. Koch, Tom F. Fondell, Joel A. Schmutz, Sarah M. Laske
*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government